Deep fat frying potatoes



Oct. 7; 1958 w. E. BUEcHELE ET AL 2,855,308

DEEP FAT FRYING POTATOES Oct. 7, 1958 w. E. Bul-:CHELE ET AL DEEP FATFRYING PoTAToEs Original Filed Oct. 1l. 1952 4 sheets-sheet 2 Oct. 7,1958 w. E. BUECHELE ErAL 2,855,308

' DEEP FAT FRYING PoTAToEs original `Filed oct. 11, 1952 4 sheets-sheets l INV NTo W r uecZe/e Jaffe Wdarasxy.

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Oct. 7, 1958 w.. E. BuEcHE-:LE ETAL 2,855,308

DEEP FAT FRYING POTATOES Original Filed Oct. .11, 1952 4 Sheets-Shed. 4

ITTORNEYS.

y assises `Patented Oct. '7, 1958 ice 2,855,308 naar rA'r rnYnsGPoTA'roEs Walter E. Enechele, Upper Darby, and Joseph W. Adacusky,Phiiadelphia, Pa., assignors to Brock & Company, lne., Fhiiadelphia,Pa., a corporation of Penn- Sylvania Original application Uctober 11,1952, Serial No. 314,278, now Patent No. 2,807,203, dated September 24,1957. Divided and this application March 11, 1957, Serial No. 645,129

2 Claims. (Cl. 99-100) The present invention relates to deep fat fryingespecially of French fried potatoes, and particularly where the Frenchfried potatoes are to be frozen.

The present application is a division of our 'application for Deep FatFrying, Serial No. 314,278, filed October 11, 1952, now Patent 2,807,203issued on September 24, 1957, and relates to the method.

A purpose of the invention is to obtain a higher retained moisturecontent in frozen French fried potatoes.

A further purpose is to avoid excessive grease penetration of Frenchfried potatoes, particularly where they are frozen.

A further purpose is to secure crisper and more tasty frozen Frenchfried potatoes.

A further purpose is to immerse the French fried potato pieces first inoil at 350 to 380 degrees F., and preferably at 375 F. for from 15 to 30seconds and preferably from 20 to 30 seconds, most desirably about 20seconds, and then to immerse the pieces of potato immediately in a bathof oil at a temperature between 250 and 300 degrees F. and preferably atabout 275 F. for 'a time of from 2 to 5 minutes and preferably about31/2 minutes, thus retaining increased moisture and reducing penetrationof oil.

Further purposes appear in the specification and in the claims.

lin the drawings we have chosen to illustrate one only of the numerousembodiments in which our invention may appear, selecting the form shownfrom the standpoints of convenience in illustration, satisfactoryoperation, and clear demonstration of the principles involved.

Figure 1 is a diagrammatic central vertical section of the deep fatfryer of the invention, the view being divided between two sheets, oneof which shows the initial portion of the mechanism on Figure 1a and theother'of which shows the final part on Figure 1b.

Figure 2 is a fragmentary top plan view of the mechanism of theinvention at the discharge end.

Figure 3 is an end elevation from the discharge end, with the finalconveyor sectioned away.

Figure 4 is an enlarged fragment `showin-g the vibration of the tray atthe point of draining. i

-Figure 5 is a fragmentary perspective showing the mechanism forvibrating at the point of draining.

Figure 6 is a fragmentary section on the line 6 6 of Figure 1b showingthe steadying conveyor.

At the present time, extensive use is being made -of French friedpotatoes which are prepared and fried and then frozen immediately afterfrying. Considerable diculty has been encountered in obtaining a Atastycrisp product which is free from excessive grease 'penetration andadherence. The present invention is designed primarily to improve thequality of frozen French Vfried potatoes, and to facilitate theproduction of the same.

It is evident from the work which we have done 'that a major cause ofpoor taste in frozen French fried po. tatoes is the tendency todehydrate the potato pieces excessively during frying, and permit greasepenetration 'to replace the moisture which has been removed. The presentinvention is designed particularly to keep moisture in the potato, andprevent grease penetration or adherence. With this purpose in view, thepotato pieces are rst caused to form a sealing skin by frying for a timeof 15 to 30 seconds and preferably 20 to 30 seconds at a temperature of350 to 380 F. and preferably about 375 F. This causes the potato toretain moisture and makes it relatively impermeable to penetration ofo-il. We then proceed with the frying operation at a relatively lowertemperature of 250 to 300 degrees F. and preferably 275 F. for a time of2 to 5 minutes and preferably about 3%. minutes. This gives a potatowhich is crisp but not hard or tough.

The pro-cess of the present invention assures of uniform cooking of thepotatoes and avoids the tendency of fragments which have becomeseparated from the dipping trays and have been burned while oatingaround in the oil bath from becoming mixed with the potatoes which arebeing cooked. In accordance with the present invention a circulationsystem is used which carries the fragments which have left the trays toa shelf which is accessible for skimming, thus preventing building up ahigh concentration of such fragments floating around the oil bath whichare likely to become mixed with the product.

One of the difficulties previously encountered has been the tendency ofthe potatoes to bunch in the trays and prevent uniform access by theoil. This is prevented by feeding the potato pieces into the trays froman apron, and vibrating the apron so that the potato pieces will bewidely spread in the trays, and desirably triggering the vibration sothat it will occur when the tray reaches the feeding point.

The conveyor is so arranged adjacent the feeding point that two upwardlydirected trays are placed one below another, and potato pieces whichfail to enter 'the upper tray are guided into the lower tray, and thusprevented from dropping into the fat bath and becoming oaters which maycause difficulty by becoming mixed with the product.

In accordance with the invention, precautions are taken to remove asmuch as possible of the adhering oil from the potatoes after they leavethe oil bath. This is do-ne by tilting the trays so that the potatoeschange their relationship with one another, and at the same timevibrating so as to remove adhering oil. The 'successive trays at thepoint of draining are arranged so that the oil dropping from upper trayswill clear lower trays and thus there will not be any tendency toredeposit cooler oil on the potatoes in lower trays.

At the point of discharge, the tray is tilted somewhat more than and asit returns to upright position is steadied by a track against violentswinging, and then desirably released and permitted to swing lightlyagainst the up-ended tray to shake out any adhering potatoes.

Considering now the structure of the drawings, a frame 20 supports asealing deep fat frying tank 21 closed at the bottom and sides and openat the top. The tank has a deep portion 22 and at its outlet end a shelfor step 23 which produces a comparatively shallow portion. The bottomslopes to the center at 24 and a drainage connection 25 is provided. Adeep fat bath 26 remains in the tank suitably to a point near the top,and is continuously recirculated through a pump outside the tank and notshown, the recirculating stream entering at the bottom near the inletand through a connection 27 and leaving at the top near the outlet andthrough a connection 28 having a series of screenedfopenings 30. The oilis heated to the desired temperature by thermostatically controlledelectric heaters 31 extending through the tank. The tank 21 ismaintained at a temperature of 350 to 380 degrees F., and preferablyabout 375 F.

3 suitably cooking the potatoes for a time of 15 to 30 seconds andpreferably about 20 seconds.

Forwardly positioned with respect to the 'tank 21 is a second deep fatfrying tank 32A which is desirably elongated, closed at the bottom andsides and open at the top. The tank 32 has a series of bottom drainingsloping portions 33 provided with drain connections 34. It is usuallyfound not to be necessary to circulate the oil in the tank 32, as thepotato fragments which may present a hazard in the tank 21 normally donot occur in appreciable quantities in the tank 32. It will be evidenthow-ever that the oil can be circulated in the tank 32 if desired.

The temperature suitably at 250.to 300 degrees F. and preferably 275 F.is maintained in tank 32 by suitable thermostatically controlledelectric heaters 35 extending across the tank near the bottom.

Positioned above the tanks is a conveyor 36 comprising spaced chains 37which are guided at suitable points where the directio-n changes orsupport is needed by rollers 38. The chains are also housed and guidedby channels 40 secured to the frame and following the course of theconveyor, but omitted for clarity in Figure 1 but shown in Figure 2.

Extending across between the chains at intervals are tray pivoting bars41 which are capable of rotating with respect to the chains and supporttrays or baskets 42 which have upper supports 43 and lower screen orperforated bottoms and sides 44 which receive the potatoes.

The conveyor is driven by a motor 45 through a chain drive 46 to speedreducers 47 and 48 which drive through a chain drive 50 to a shaft 51which extends across to the opposite side of the conveyor and isinterconnected by chain drives 52 and 53 to shaft -54 supported onsuitable bearings and driving the respective conveyor chains throughsprockets 55 which engage the conveyor chains. The shafts have suitablebearing support in the frame.

Suitably diced potato pieces are introduced to the fryer l' by conveyor56 traveling upwardly and driven by drive 57, the potatoes beingdischarged through hopper 53 on to forwardly and downwardly inclinedapron 60. The inclination of the apron is less than the angle o-f reposeof the potato pieces resting on the apron, so that the potato pieceswill not discharge from the apron merely by sliding off under gravityaction. The apron is supported by cables 61 which engage the rearwardend, and at the forward end is interconnected with vibrating machine 62which is supported by cable 63 and will desirably be a Syntron vibratoras well known in the art, which causes the apron to be shaken forwardlyand backwardly when the vibrator is electrically energized by startingits driving motor. An electric switch 64 is desirably placed with itsfeeler in position to be tripped by the pivot bar 41 of a tray whichreaches loading position 65, thus energizing the vibrator 62 momentarilyand causing potato pieces on the apron to be thrown forward in widelydistributed relationship into the tray at loading position 65 to loadthe tray.

Immediately forward of the loading position 65 the conveyor makes areverse bend at 66 and as the trays are self-leveling they turn aroundwith respect to the conveyor chain and one of the trays reaches aposition 67 beneath the loading position. ln this position the tray isable to catch potato pieces which drop from the loading position andthis is aided by a downwardly sloping bale 68 which directs suchoverflow potato pieces into ythe lower tray.

From the loading position the conveyor after making the reverse benddips downwardly at 70 bringing successive trays into the sealing cookingposition 71 in which the potatoes in the tray are immersed in the deepfat bath 26. The conveyor at the forward end of the deep fat tank risesupwardly at 72 and at a tray position 73 carries the trays over theseparating wall between sealing cooking tank 21 and second frying tank32, after which the conveyor is carried downwardly at 74 and brings the4 tray into deep fat frying position at 75 to travel along beneath thelevel of the deep fat bath of the second frying tank 32.

In each of the deep fat frying tanks there is a centrally horizontalconveyor 59 or 59', as the case may be, driven by a drive 592 or 593 asthe case may be which is interconnected with the main conveyor. Theconveyors have upper forwardly extending stretches moving throughchannels 594 supported by legs 595 from the tank. The forward stretchmoves immediately beneath the trays in the tank and steadies themtraveling forward at the same rate as the trays. The conveyor is shownin detail in Y lFigure 6.

At the forward end of the second frying tank the conveyor begins totravel diagonally upwardly and forwardly at 76, raising the tray whichhas just left the second deep fat bath to position 77 at which theforward end of the tray encounters vibrating bar 78 which is best seenin Figures 4 and 5. The bar extends fully across the tray, and suitablyhas bearing support at 80 at one end, and has freedom to vibratevertically at the other end in a guide slot 81 on the frame. Thevibratory action is provided by vibrating motor 82 which through beltand pulley system 83 drives shaft 84 carrying eccentric 35 whichpivotally connects to connecting rod 86 which at its upper end issecured to the vibrating bar 78 as by welding.

The vibrating bar is close enough to the tray to tilt the tray at theposition 77 and cause the potato pieces to move to the forward end andcause the successive trays above the position 77 at 87, 88, 90, and 91,each a little forward of the other because of the forward conveyormotion, to tilt slightly due to the overloading of the forward portion,so that the dripping of the fat which is promoted by the vibrating bar'73 and continues in the successive upper positions doesnot cause fat todrop on potatoes in lower baskets, the drippings falling forwardly andclear of the lower basket and being received by a dripping return chute92 which brings the drippings back into the fat bath.

The conveyor now moves across through a substantially horizontal portion93 to a position at which the successive trays encounter tilting barwhich extends across beneath the chains and tip-ends the trays as shownat position 95, dropping the potatoes into hopper 96 from'the bottom ofwhich the potatoes discharge to apron 9'7 which is continuously vibratedby mechanism at 98 as well known. The apron is suspended by cables 100and the vibrating mechanism is suspended by cables 101. From thevibrating discharge apron the potatoes which have now finished thefrying operation pass to freezing conveyor 102 which carries them intoquick freezing chamber 103, in case they are to bc frozen.

In operation it will be evident that the potatoes are loaded into a trayat the loading position 65 by vibrating of the apron 60 desirably inresponse to the movement of the conveyor bringing that tray to theloading position. Any excess of potatoes are picked up by a basket belowthe basket being loaded. The successive loaded trays are then immersedin the first sealing deep fat bath, and any floating potatoes `in thatbath are taken by the recirculating stream to a shelf at the forward endfrom which they can be removed by hand skimming. Trays are then carriedto the second deep fat frying bath, after which they are removed,tilted, and vibrated to eliminate excess of grease, and Icarriedupwardly and forwardly in a slightly inclined tray position so thatdripping grease will not encounter potatoes below. The trays are thenupended to discharge the potatoes. lf the up-ended tray at 95 wereallowed to swing free there would be danger that it would strike othertrays and cause damage, and therefore a cam track 104 is providedbeneath the upended tray as it passes beyond the tilting bar 94, whichgradually curves downwardly at 105 and thus-permits the tray to returnto upright position as the conveyor moves forwardly.

As soon Vas the upward moving tray 106 is released by the track 104 itis free to swing and by swinging lightly touches the discharging tray95, shaking out any potatoes which tend to adhere.

In view of our invention and disclosure variati-ons and modications tomeet individual whim or particular need will doubtless become evident toothers skilled in the art, to obtain all or part of the beneits of ourinvention without copying the method, and we therefore claim all suchinsofar as they fall within the reasonable spirit and scope of ourclaims.

Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. The method of French frying potatoes in deep fat, which comprisesslicing the potatoes, immersing the potatoes in melted fat at atemperature of 350 to 380 F. for

a time of 15 to 30 seconds and thus forming a skin on the potatoes,immediately withdrawing the potatoes and immersing the potatoes in deepfat at a temperature of 250 to 300 F. for a time of 2 to 5 minutes andremoving the potatoes from the deep fat.

2. The method of French frying potatoes in deep fat, which comprisesdicing the potatoes, immersing the diced potatoes in deep fat at `atemperature of about 375 F. for a time of 20 to 30 seconds and thusforming :a skin on the potatoes, immediately removing the potatoes fromthe deep fat :and immersing the potatoes in another bath of deep fat ata temperature of 275 F. for a time of about 31/2! minutes and removingthe potatoes from the deep fat.

References Cited in the tile of this patent UNITED STATES PATENTS2,056,884 Brunstetter Oct. 6, 1936 2,286,644 Pringle etal `Tune 16, 19422,715,869 Salvo Aug. 23, 1955

1. THE METHOD OF FRENCH FRYING POTATOES IN DEEP FAT, WHICH COMPRISESSLICING THE POTATOES, IMMERSING THE POTATOES IN MELTED FAT AT ATEMPERATURE OF 350 TO 350*F. FOR A TIME OF 15 TO 30 SECONDS AND THUSFORMING A SKIN ON THE PTATOES, IMMEDIATELY WITHDRAWING THE POTATOES ANDIMMERSING THE POTATOES IN DEEP FAT AT A TEMPERATURE OF 250 TO 300*F. FORA TIME OF 2 TO 5 MINUTES AND REMOVING THE POTATOES FROM THE DEEP FAT.